Upgrade your productivity, and save your posture, with the 12 best office chairs that are on sale as part of Amazon's October Prime Big Deal Days.

Another great deal is on the Razer Enki X, which is on sale for just $299.99 (was $399.99) at Amazon. Read on for even more deals if you want to save some cash on a gaming chair this Amazon Prime Day. • Shop more Prime Day deals

A step up from Branch's Daily Chair, the Ergonomic Chair pays extra attention on providing your back with much-needed cushion and support. It has adjustable lumbar support and seven (!) other points of adjustment, including the seat depth, armrest height, and more. So if you're looking for an extremely versatile pick, this one is a great option.